206 EVENINGS AT THE MICEOSCOPE. 



saw in the Cyclops, of several lenses, enveloped in a 

 common cornea, the whole forming a movable organ 

 of a blue-black hue. Just behind this, at the very 

 highest part of the shell, is a little colourless bladder- 

 like vesicle, which constantly maintains a rapidly alter- 

 nate contraction and dilatation. This is the heart, and 

 this motion circulates the blood. 



Below this, there is seen a great translucent irregu- 

 lar mass of flesh, evidently comprising many viscera, 

 which winds along from one end of the shell to the 

 other, nearly occup3nng its entire area, but not in con- 

 nexion with it at the hinder part, as we see by its free 

 movements there, where it curves round, and bending 

 beneath terminates in a blunt tail, armed with two 

 strong hooks, which can at pleasure be thrust down 

 through the narrow orifice of the shell, and become par- 

 tially sti'aightened by being forcibly thrown backward 

 This great central mass is mainly occupied by the ali- 

 mentary canal, in which food in various stages of assim- 

 ilation may at all times be seen, and in which the 

 inteiosting function of digestion can be M'itnessed 

 throughout, from the first seizure of the atom and its 

 mastication by the jaws, to the discharge of the effeta 

 remains. 



The individual before us does not carry at this time 

 eggs in the process of development; but the deficiency 

 is supplied by a Da_phnia^^'\neh is playing about in the 

 same drop of water. Here you perceive, between the 

 arched outline of the shell and the sinuous outline of the 

 free soft bod}^, an open space of some size, which con- 

 stitutes a receptacle, in which the eggs are deposited as 

 they are laid, and in which they remain not only until 

 tlie little animals are hatched, but until thev have ac- 



